Official Statistics

Annual commentary on MRSA, MSSA and Gram-negative bacteraemia and Clostridiodies difficile infections from independent sector healthcare organisations in England: April 2022 to March 2023

Updated 17 November 2023

UK Health Security Agency and this report

Beginning in April 2021, the UK Health Security Agency (UKHSA) was created and is responsible for protecting every member of every community from the effect of infectious diseases, chemical, biological, radiological, and nuclear incidents and other health threats. We provide intellectual, scientific, and operational leadership at national and local level, as well as on the global stage, to make the nation’s health secure.

The agency replaces Public Health England (PHE) and is an executive agency of the Department of Health and Social Care (DHSC). The transition to UKHSA included the integration of both staff and systems. Accordingly, the systems and processes responsible for the publication of the previous annual epidemiological commentaries were incorporated into UKHSA. The same methods of data capture, analysis and dissemination have been employed in the production of this report.

Correction notice

This report was initially published on 24 October 2023 and later revised on 17 November 2023 due to unscheduled corrections to some manual processing errors identified following initial publication of these statistics.

Corrections have resulted in revised data presented for 3 independent sector organisations including Circle Health, Nuffield Health and Spire Healthcare. This includes:

• the status of 4 Nuffield Health hospitals (previously reporting as being closed, not opened, between April 2022 and March 2023)
• the number of hospitals in Nuffield Health and Spire Healthcare between April 2022 and March 2023
• the numbers of modified bed-days for Circle Health, Nuffield Health and Spire Healthcare between April 2022 and March 2023

These revisions have subsequently resulted in reduced infection incidence rates at organisation level and overall, as summarised in this report.

All revised figures have been updated within this report and the accompanying OpenDocument Spreadsheet.

Executive summary

Between 1 April 2022 and 31 March 2023, 126 cases of E. coli bacteraemia, 101 cases of Klebsiella spp. bacteraemia, 45 cases of P. aeruginosa bacteraemia, 4 cases of meticillin resistant S. aureus (MRSA) bacteraemia, 31 cases of meticillin sensitive Staphylococcus aureus (MSSA) bacteraemia, and 54 cases of Clostridioides difficile infections (CDI) were reported by Independent Sector (IS) healthcare providers.

Of the 24 IS healthcare organisations, 17 provided bed occupancy data. Among IS providers with occupancy data, the highest incidence rate was in E. coli bacteraemia (7.7 per 100,000 bed-days plus discharges, n=122), while the lowest rate was in MRSA bacteraemia (0.3 per 100,000 bed-days plus discharges, n=4).

Incidence rates per 100,000 bed-days plus discharges for the other infections were:

• Klebsiella spp. bacteraemia (6.3, n=100)
• CDI (3.4, n=54)
• P. aeruginosa bacteraemia (2.8, n=45)
• MSSA bacteraemia (1.8, n=28)

These figures include all cases reported by the IS and does not take into account whether or not the infection was thought to be associated with the IS organisation. Below is a summary of key differences between the NHS and IS which should be considered (Table 1).

Table 1. Summary of key differences between the NHS and IS

Independent sector organisations	NHS acute trusts
Data are not classified based on onset of the bacteraemia of infection	Data are categorised into ‘Hospital-onset’ and ‘Community-onset’ cases. ‘Hospital-onset’ cases are those thought to have been associated with a given NHS Trust during an associated hospital admission, while ‘Community-onset’ cases are not associated with a current hospital admission. However, ‘Community-onset’ cases are not all community-associated, as patients may have had prior healthcare interactions.
Primarily elective patient-mix	Broad patient-mix including emergency-based treatments
Constantly changing facility list	Mainly static list of providers
Large number of specialist facilities	Mainly general acute facilities
Organisations may comprise geographically diverse hospitals	Mainly local clusters of hospitals
Rates calculated using bed-days plus discharges due to the high proportion of day cases compared to the NHS	Mostly rates are calculated using bed-days (occupied beds at midnight - inpatient bed-days figures are available online) or population.

Introduction

This report is the latest in a series of publications of healthcare-associated infections (HCAI) surveillance data on MRSA, MSSA and Gram-negative (E. coli, Klebsiella spp. and P. aeruginosa) bacteraemia and CDI reported by independent sector (IS) healthcare organisations to UKHSA. IS healthcare organisations providing regulated activities (see The Health and Social Care Act 2008 (Regulated Activities) Regulations 2010) undertake surveillance on HCAIs and report identified cases to UKHSA as specified in the Code of Practice.

Patient level data is provided to UKHSA via the secure Data Capture System (DCS) and the data for this publication was extracted on 8 September 2023.

Presentation of data

Counts and rates (per 100,000 bed-days and discharges) of MRSA, MSSA, E. coli, Klebsiella spp. and P. aeruginosa bacteraemia and CDI are presented by IS organisation for the 12-month period 1 April 2022 and 31 March 2023. (An IS organisation can comprise a group of hospitals owned by one company or a single hospital. It is possible to identify a group versus a hospital using the ‘number of hospitals in organisation’ field.)

The modified inpatient bed-days (bed-days plus discharges) are provided for the most recent financial year available (April 2022 to March 2023) as an indication of the size of each facility.

The hospital type (large hospital = 49 beds or more, small hospital = less than 50 beds, NHS treatment centre, diagnostic centre seeing mainly day case patients and women’s health) is listed for the hospitals within a group. This indicates the type of services provided (where a group comprises more than one hospital type, all types are listed). This is correct as of 3 September 2023 based on information supplied to UKHSA.

Additional information can be found in the accompanying OpenDocument Spreadsheet. Some IS organisations included in the data tables may have not been reporting for the entire period. Such hospitals are included in Appendix 2. Cases among renal patients have been excluded.

Interpreting the data

The data are available in the accompanying OpenDocument Spreadsheet and shows counts and rates of all reported cases of:

• E. coli bacteraemia by Independent Sector Healthcare Organisation – April 2022 to March 2023 (Table T1)
• Klebsiella spp. bacteraemia by Independent Sector Healthcare Organisation – April 2022 to March 2023 (Table T2)
• P. aeruginosa bacteraemia by Independent Sector Healthcare Organisation – April 2022 to March 2023 (Table T3)
• MRSA bacteraemia by Independent Sector Healthcare Organisation – April 2022 to March 2023 (Table T4)
• MSSA bacteraemia by Independent Sector Healthcare Organisation – April 2022 to March 2023 (Table T5)
• CDI by Independent Sector Healthcare Organisation – April 2022 to March 2023 (Table T6)

The data does not provide:

• a basis for comparisons between different IS organisations, due to their variable size and range (case mix) of patients seen
• a basis for reliable comparison of these infections between the NHS and IS organisations

A full discussion of these issues is presented elsewhere. The reasons behind this are discussed in Commentary on Reporting of C. difficile infections and MRSA bacteraemia from the Independent Sector, published 2009.

Specific data caveats

Below is a list of specific caveats to be considered in relation to the published data.

Data quality

Not all IS organisations have signed off their data or submitted data for the reporting period. Data for such organisations may not yet be finalised and therefore may not be accurate. IS organisations that have not signed off their data for the time period are highlighted in the accompanying OpenDocument Spreadsheet.

Duplicate entries

Data entered onto the DCS by the NHS and IS are collected in two parallel systems. This means that data on a single case may be entered by either an NHS trust, an IS organisation, or both. Data have only been de-duplicated against the NHS dataset for cases reported via the DCS. If a case is reported by an IS provider and an NHS acute trust, the IS case is excluded as a duplicate entry if:

• the NHS case was reported with a patient location of “NHS acute trust”, and the IS case was reported with a patient location that is not “IS provider”

• the NHS case was reported with a patient location of “NHS acute trust” and the IS case was reported with a patient location of “IS provider” but has a specimen date within 14 days (28 days for CDI) prior to the NHS case

Cases are only de-duplicated if they are reported by both IS providers and NHS Acute Trusts. Multiple cases reported only by one or more IS providers are not de-duplicated. Additionally, NHS number, which is one of the variables used to de-duplicate records, is not always known for patients treated in the IS, so some duplicate records entered onto the DCS may not be identified.

Organisational changes

Some IS organisations included in the data tables may have not been open for the entire reporting period, whilst others may have closed over this time. This may reduce the count of these infections in such IS organisations, compared to those that were open for the whole period. However, this will also be reflected in their bed occupancy data, so any rate calculated still has validity over the shorter period. Such organisations are listed in Appendix 2.

Results

This report includes 24 organisations, 10 of which are groups of more than one hospital and the remaining 14 are single hospitals. Occupancy data (inpatient bed-days plus discharges – see Appendix 2 for further details) was available for 17 organisations. Individual rates for these organisations are included in the accompanying OpenDocument Spreadsheet.

E. coli bacteraemia (Table T1)

A total of 126 cases of E. coli bacteraemia were reported from April 2022 to March 2023 by the following organisations:

• HCA International (81 cases)
• The London Clinic (16 cases)
• Spire Healthcare (8 cases)
• BUPA Cromwell Hospital (6 cases)
• Nuffield Health (6 cases)
• Circle Health (4 cases)
• Ramsay Health Care UK (3 cases)
• Aspen Healthcare (1 case)
• Royal Hospital for Neuro-disability (1 case)

Among IS providers that provided their modified inpatient bed-days, the incidence rate of E. coli bacteraemia for April 2022 to March 2023 was 7.7 cases (n=122) per 100,000 bed-days plus discharges.

Klebsiella spp. bacteraemia (Table T2)

A total of 101 cases were reported from April 2022 to March 2023 by the following organisations:

• HCA International (72 cases)
• BUPA Cromwell Hospital (11 cases)
• The London Clinic (11 cases)
• Nuffield Health (4 cases)
• Circle Health (2 cases)
• The New Victoria Hospital Ltd (1 case)

Among IS providers that provided their modified inpatient bed-days, the incidence rate of Klebsiella spp. bacteraemia for April 2022 to March 2023 was 6.3 cases (n=100) per 100,000 bed-days plus discharges.

Pseudomonas aeruginosa bacteraemia (Table T3)

A total of 45 cases were reported from April 2022 to March 2023 by the following organisations:

• HCA International (31 cases)
• The London Clinic (7 cases)
• BUPA Cromwell Hospital (5 cases)
• Nuffield Health (1 case)
• The Hospital of St John & St Elizabeth (1 case)

Among IS providers that provided their modified inpatient bed-days, the incidence rate of P. aeruginosa bacteraemia for April 2022 to March 2023 was 2.8 cases (n=45) per 100,000 bed-days plus discharges.

MRSA bacteraemia (Table T4)

A total of 4 cases were reported from April 2022 to March 2023 by HCA International. No cases were reported by the other organisations.

Among IS providers that submitted their modified inpatient bed-days data, the incidence rate of MRSA bacteraemia for April 2022 to March 2023 was 0.3 cases (n=4) per 100,000 bed-days plus discharges.

MSSA bacteraemia (Table T5)

A total of 31 cases were reported from April 2022 to March 2023 by the following organisations:

• HCA International (13 cases)
• BUPA Cromwell Hospital (5 cases)
• Nuffield Health (4 cases)
• The London Clinic (3 cases)
• Spire Healthcare (2 cases)
• The Royal Buckinghamshire Hospital Ltd (2 cases)
• Circle Health (1 case)
• Ramsay Health Care UK (1 case)

Among IS providers that provided their modified inpatient bed-days, the incidence rate of MSSA bacteraemia for April 2022 to March 2023 was 1.8 cases (n=28) per 100,000 bed-days plus discharges.

C. difficile infection (Table T6)

A total of 54 cases were reported from April 2022 to March 2023 by the following organisations:

• HCA International (36 cases)
• Spire Healthcare (6 cases)
• Royal Hospital for Neuro-disability (4 cases)
• The London Clinic (3 cases)
• Nuffield Health (2 cases)
• BUPA Cromwell Hospital (1 case)
• Circle Health (1 case)
• The Hospital of St John & St Elizabeth (1 case)

Among IS providers that provided their modified inpatient bed-days, the incidence rate of P. aeruginosa bacteraemia for April 2022 to March 2023 was 3.4 cases (n=54) per 100,000 bed-days plus discharges.

Official Statistics in Development

These statistics are badged as Official Statistics in Development (previously labelled ‘experimental statistics’). Official statistics in development are developed under the guidance of the Head of Profession for Statistics. The goal is to develop statistics that can, in due course, be produced to the standards of the Code of Practice for Statistics. This statement provides further detail on the nature of the development and how we are continuing to assess these statistics against the Code of Practice.

While the current statistics undergo a standardised quality assurance process, there are some known limitations, as outlined in the specific data caveats section of this report. This includes many IS organisations not having signed off their data for the reporting year. For mandatory surveillance of healthcare-associated infections, data must be signed off on a monthly basis. In the case of IS organisations, this responsibility is held by the ‘authorised person’, who is defined as a senior manager within the organisation. This process provides additional reassurance that the data included in a period have been verified. 

There is a public need for this information as it provides annual counts and rates for healthcare-associated infections under mandatory surveillance by independent sector organisations. Therefore, these statistics are published as Official Statistics in Development to meet user need, whilst being transparent on potential data quality concerns.

During the next 12 months, UKHSA will:

• explore options for improving sign-off coverage of data received by independent sector organisations
• consult with key stakeholders, including independent sector organisations, to understand the usage of the statistics

The results of these actions will be used to inform the decision regarding the publication status of the 2023 to 2024 HCAI surveillance data by IS healthcare organisations.

Our statistical practice is regulated by the Office for Statistics Regulation (OSR). OSR sets the standards of trustworthiness, quality and value in the Code of Practice for Statistics that all producers of official statistics should adhere to. 

You can contact us directly by emailing mandatory.surveillance@ukhsa.gov.uk with any comments about how we meet these standards. Alternatively, you can contact OSR by emailing regulation@statistics.gov.uk or via the OSR website.

Appendix 1: How to calculate bed-day plus discharge denominator

The denominator used, which is more appropriate for shorter stay hospitals, is the sum of the number of bed-days in year added the number of discharges in year.

Instead of counting only the number of nights the patient was resident at midnight for, as per the denominator used for NHS rate calculations, this counts the number of different days a patient was in the hospital. A day case will count as one bed-day plus discharges, (calculated as 0 midnights but one discharge) while a one night stay in the year will count as 2 bed-days plus discharges (calculated as one midnight residence and one discharge).

 Bed-days in the financial year April 2022 to March 2023

Bed-days in the financial year is the sum of the number of occupants in a bed each midnight during the year, for example, the sum of the number of bed occupants at midnight day end 1 April 2022 added to the number of bed occupants at midnight for each subsequent day up to and including 31 March 2023. 

If the bed-days is being derived from admission dates and discharge dates, you work out the contribution that each patient makes to the year’s bed-days by a formula. 

Only patients who are admitted to hospital before 1 April 2023 and discharged on or after 1 April 2022 are counted towards a bed-day in that financial year. That is, the latest date they could have been admitted was 31 March 2023 and the earliest date they could have been discharged was 1 April 2022. 

This is calculated as the discharge date or 1 April 2023 (whichever is earlier) minus the admission date or 1 April 2022 (whichever is later) and added to the sum of all patients. 

This counts the number of bed-days the patient contributes to the year. 

If the patient is still in hospital and does not yet have a discharge date, then the first expression should be taken as 1 April 2023.

Discharges in the financial year April 2022 to March 2023

Discharges are counted as the number of patients with a discharge date between 1 April 2022 and 31 March 2023, that is, the sum of the number of patients discharged on 1 April 2022 added to the number discharged for each subsequent day up to and including 31 March 2023.

It should include any day cases that took place during the year.

Figures provided should be aggregated for each organisation (where an organisation owns more than hospital or facility) or for the individual hospital if an organisation comprises one hospital or facility.

Appendix 2: Organisational changes among IS providers during the reporting period; April 2022 to March 2023

(This data was correct as at 3 September 2023 and as supplied to UKHSA).

Table 2. Hospitals that closed, opened, changed ownership or ceased during the reporting; April 2022 to March 2023

IS Provider Name	Site Name	Status	Month
Nuffield Health	Nuffield Health Highgate Hospital	Changed ownership	June 2022
Nuffield Health	Nuffield Health The Holly Hospital	Changed ownership	June 2022
Nuffield Health	Nuffield Health Parkside Hospital	Changed ownership	June 2022
Nuffield Health	Nuffield Health at St Bartholomew’s Hospital	Opened	May 2022
Spire Healthcare	Spire Hospital Hastings	Closed	April 2022